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Roller Rocker Arm Adjustment (stud mount).

23K views 12 replies 9 participants last post by  DanH  
#1 ·
I’m using the following procedure:
Starting with #1 cylinder and going through the firing order. When the exhaust valve just starts to open, I put the intake to zero lash, tightened nut ½ turn, tighten set screw, then turn nut 1/8 turn. When intake fully opens and just starts to close, I put the exhaust to zero lash, tightened nut ½ turn, tighten set screw, then turn nut 1/8 turn.

After I set each valve then go back to #1 cylinder the rockers can be moved side-to-side by hand, but they are at zero lash. I assumed the rocker arms wouldn’t move. Is this normal and if not what I’m I doing wrong?
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#2 ·
The rockers will move a little side to side, that is ok.

But i dont understand one thing. Why are you turning the adjustment nut another 1/8 turn? Once you set the lock nut, that is it.

So to recap... you make sure there is no lash..i.e. the pushrod has no movement between the rocker and lifter. Then turn the adjustment nut on the rocker 1/2 - 3/4 turn. This is the preload. Than you hold it in place and lock the allen screw. Done.
 
#10 ·
But i dont understand one thing. Why are you turning the adjustment nut another 1/8 turn?
He is using a common technique to increase the set-screw's holding power by increasing interference between the adjuster and set-screw, but also between the adjuster nut and stud threads. I use the same technique. Every adjuster set/type has a different thread form (production variance) and material hardness that causes the set-screw torque to place more or less jamming force on the adjuster nut. This technique he's talking about ensures that the stud, nut, and set-screw are at greater interference and are more secure.

With a few test torques with each new set to establish where to pre-tighten the set-screw so adjustment with the additional turning (you turn both wrenches together) ends-up at the correct setting, solid lifter valve trains are accurately done the same way. The last set I adjusted was with TFS studs and Sig Erson adjusters, and the additional turning to reach about 25 ft/lb (my personal target by feel) was just over 1/16 turn for that particular combination and the tools I was using.
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David
 
#3 ·
I went through the same procedure and it still wasn't quite right.
I found that a better method is to write down the firing order on a piece of paper, putting the first four cylinders in order above the last four.
--
221-302 firing order
1-5-4-2
6-3-7-8
--
351 firing order (make sure it hasn't been changed
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1-3-7-2
6-5-4-8
Then as the intake just starts to open on the one at the top, adjust the corresponding number cylinder under it on the paper using the '0 lash, 1/2 turn' deal you describe. So in the 302 order you would see IN #1 start to lift - adjust the EX on #6, then as IN#5 started to lift, do EX#3 and so on.
Don't tighten them any more than the 1/2 to 2/3 (where's you get the 1/8th from?). Once you've done the first four, swap the theory for the 'bottom' four, then start again watching for EX lift to do the intakes.
Yes, I know it might take bloody ages, but this is the only guarenteed method for getting it spot on (especially if you're having any trouble with the straight 'firing order' method you have described.
 
#6 ·
As codeblu says, thats exactly what i do, with engine cold enough to work on I put each cylinder on compression stroke & adjust both intake/exhaust to zero lash, turning until the pushrod is stiff to turn, then another 1/2 to 3/4 turn of adj.nut & hold it in place & tighten allen head, if you turn the adj. nut another 1/8 turn your throwing out all you.ve just done, aren;t you?
This way has proved fool proof for me, if there is something wrong with this so simple method, do tell
 
#11 ·
Now that's what I like, more then one way to skin a cat. and using Crane roller rocker arms on a hyd cam, they did make a little noise after adjusted.
I do mine the old fashion way, but I also have special cut out valve covers to do it with. I always just adjust the outer nuts finger tight, while hand jacking over the engine about 5 complete turns, then a 1/4 turn more. That gives be a starting setting.
Then with the engine idling I do the turn open till it clacks then slowly turn till it stops, then 1/4 turn more. Have to be fast and can take a few times. Messy to with oil spraying at times.
Once each side is done, (engine off now) then I turn the outer nut 1/16 of a turn more, screw down the allen lock nut. Hold the allen screw and twist the nut and screw against each other, which takes out the 1/16 of a turn I put in. That locks them together in place. Never had any ARPs nuts loosen on me that way and good to 6800 rpms on a Crane Hyd cam.
Solid cams are easier and done the same as you would regular rocker arms.
 
#12 ·
i have hydralic lifters and i have adjusted them every way possilbe and i lose all my power when i gave it a half to 3/4 of a turn and i also bent a valve in the process. but when i adjust them a 1/4 of a turn after zero lash my goodness the engine performs great its just that they are a lil noisy